A metal sphere with radius $1\mathrm{.}00$ cmcm is supported on an insulating stand at the center of a hollow, metal, spherical shell with radius rbrb $=9\mathrm{.}60$ cmcm$.$ Charge $+$q$+$q is put on the inner sphere and charge $$q$$q on the outer spherical shell. The magnitude of qq is chosen to make the potential difference between the spheres $500$ VV$,$ with the inner sphere at higher potential.